County Data Sets have become Statewide Data Sets

Grant funding from the USGS created an opportunity to implement file format changes for statewide and county Illinois Map Data Layers which had been available for download since July of 1997. We are pleased that these improvements enable us to better serve the Illinois GIS user community.

County Boundaries
Available as a statewide data layer on the Base Data and PLSS Data page.
Airports
Replaced by the statewide data layer Geographic Names Information System (GNIS) on the Administrative and Infrastructure Data page.
Archaeological Resource Potential
Available as a statewide data layer on the Administrative and Infrastructure Data page.
1990 Census Blocks
Distribution of U.S. Census data for Illinois is discontinued, refer to U.S. Census Bureau
Flood Zones for Unincorporated Places, 100 and 500 Year
Available as a statewide data layer on the Hydrology and Water Resources Data page.
Municipalities
Available as a statewide data layer on the Administrative and Infrastructure Data page.
Towns
Replaced by the statewide data layer Geographic Names Information System (GNIS) on the Administrative and Infrastructure Data page.
Active and Abandonded Railroads
Distribution of railroads data for Illinois is discontinued. The data set formerly available was out of date and incomplete. It did not provide ownership information on railroad lines.
Streets and Highways
Statewide data sets are already available for Interstates, U.S. Highways, and State Routes on the Administrative and Infrastructure Data page. Also, refer to Illinois Department of Transportation Technology Transfer Center
Streams and Shorelines
Available as a statewide data layer on the Hydrology and Water Resources Data page. Also, refer to Illinois Streams Information System
Towns or Populated Places
Replaced by the statewide data layer Geographic Names Information System (GNIS) on the Administrative and Infrastructure Data page.
Township Lines
A statewide data set is already available for Township and Range Lines on the Base Data and PLSS Data page.
Electrical Transmission Lines and Pipelines
Distribution of the Electrical Transmission Lines and Pipelines (Utility) data for Illinois is discontinued. The data set formerly available was out of date and incomplete. It did not provide ownership information on utility lines. Contact the National Pipeline Mapping System for Illinois pipeline data.
Wells and Borings
Refer to the ISGS ArcIMS Interactive Map Services for Illinois Water and Related Wells and Illinois Oil and Gas Resources.
Illinois Wetlands Inventory (Points, Lines, and Polygons)
Available as a statewide data layer on the Hydrology and Water Resources Data page. Also, refer to U.S. Fish and Wildlife Service, National Wetlands Inventory